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//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2009-2012. Distributed under the Boost
// Software License, Version 1.0. (See accompanying file
// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// See http://www.boost.org/libs/interprocess for documentation.
//
//////////////////////////////////////////////////////////////////////////////
#ifndef BOOST_INTERPROCESS_XSI_SHARED_MEMORY_HPP
#define BOOST_INTERPROCESS_XSI_SHARED_MEMORY_HPP
#if defined(_MSC_VER)
# pragma once
#endif
#include <boost/interprocess/detail/config_begin.hpp>
#include <boost/interprocess/detail/workaround.hpp>
#include <boost/detail/workaround.hpp>
#if !defined(BOOST_INTERPROCESS_XSI_SHARED_MEMORY_OBJECTS)
#error "This header can't be used in operating systems without XSI (System V) shared memory support"
#endif
#include <boost/interprocess/creation_tags.hpp>
#include <boost/interprocess/exceptions.hpp>
#include <boost/interprocess/detail/utilities.hpp>
#include <boost/move/utility_core.hpp>
#include <boost/interprocess/detail/os_file_functions.hpp>
#include <boost/interprocess/interprocess_fwd.hpp>
#include <boost/interprocess/exceptions.hpp>
#include <boost/interprocess/xsi_key.hpp>
#include <boost/interprocess/permissions.hpp>
#include <sys/shm.h>
#include <cstddef>
#include <boost/cstdint.hpp>
//!\file
//!Describes a class representing a native xsi shared memory.
namespace boost {
namespace interprocess {
//!A class that wraps XSI (System V) shared memory.
//!Unlike shared_memory_object, xsi_shared_memory needs a valid
//!xsi_key to identify a shared memory object.
//!
//!Warning: XSI shared memory and interprocess portable
//!shared memory (boost::interprocess::shared_memory_object)
//!can't communicate between them.
class xsi_shared_memory
{
#if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
//Non-copyable and non-assignable
BOOST_MOVABLE_BUT_NOT_COPYABLE(xsi_shared_memory)
#endif //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
public:
//!Default constructor.
//!Represents an empty xsi_shared_memory.
xsi_shared_memory();
//!Initializes *this with a shmid previously obtained (possibly from another process)
//!This lower-level initializer allows shared memory mapping without having a key.
xsi_shared_memory(open_only_t, int shmid)
: m_shmid (shmid)
{}
//!Creates a new XSI shared memory from 'key', with size "size" and permissions "perm".
//!If the shared memory previously exists, throws an error.
xsi_shared_memory(create_only_t, const xsi_key &key, std::size_t size, const permissions& perm = permissions())
{ this->priv_open_or_create(ipcdetail::DoCreate, key, perm, size); }
//!Opens an existing shared memory with identifier 'key' or creates a new XSI shared memory from
//!identifier 'key', with size "size" and permissions "perm".
xsi_shared_memory(open_or_create_t, const xsi_key &key, std::size_t size, const permissions& perm = permissions())
{ this->priv_open_or_create(ipcdetail::DoOpenOrCreate, key, perm, size); }
//!Tries to open a XSI shared memory with identifier 'key'
//!If the shared memory does not previously exist, it throws an error.
xsi_shared_memory(open_only_t, const xsi_key &key)
{ this->priv_open_or_create(ipcdetail::DoOpen, key, permissions(), 0); }
//!Moves the ownership of "moved"'s shared memory object to *this.
//!After the call, "moved" does not represent any shared memory object.
//!Does not throw
xsi_shared_memory(BOOST_RV_REF(xsi_shared_memory) moved)
: m_shmid(-1)
{ this->swap(moved); }
//!Moves the ownership of "moved"'s shared memory to *this.
//!After the call, "moved" does not represent any shared memory.
//!Does not throw
xsi_shared_memory &operator=(BOOST_RV_REF(xsi_shared_memory) moved)
{
xsi_shared_memory tmp(boost::move(moved));
this->swap(tmp);
return *this;
}
//!Swaps two xsi_shared_memorys. Does not throw
void swap(xsi_shared_memory &other);
//!Destroys *this. The shared memory won't be destroyed, just
//!this connection to it. Use remove() to destroy the shared memory.
~xsi_shared_memory();
//!Returns the shared memory ID that
//!identifies the shared memory
int get_shmid() const;
//!Returns the mapping handle.
//!Never throws
mapping_handle_t get_mapping_handle() const;
//!Erases the XSI shared memory object identified by shmid
//!from the system.
//!Returns false on error. Never throws
static bool remove(int shmid);
#if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
private:
//!Closes a previously opened file mapping. Never throws.
bool priv_open_or_create( ipcdetail::create_enum_t type
, const xsi_key &key
, const permissions& perm
, std::size_t size);
int m_shmid;
#endif //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
};
#if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
inline xsi_shared_memory::xsi_shared_memory()
: m_shmid(-1)
{}
inline xsi_shared_memory::~xsi_shared_memory()
{}
inline int xsi_shared_memory::get_shmid() const
{ return m_shmid; }
inline void xsi_shared_memory::swap(xsi_shared_memory &other)
{
std::swap(m_shmid, other.m_shmid);
}
inline mapping_handle_t xsi_shared_memory::get_mapping_handle() const
{ mapping_handle_t mhnd = { m_shmid, true}; return mhnd; }
inline bool xsi_shared_memory::priv_open_or_create
(ipcdetail::create_enum_t type, const xsi_key &key, const permissions& permissions, std::size_t size)
{
int perm = permissions.get_permissions();
perm &= 0x01FF;
int shmflg = perm;
switch(type){
case ipcdetail::DoOpen:
shmflg |= 0;
break;
case ipcdetail::DoCreate:
shmflg |= IPC_CREAT | IPC_EXCL;
break;
case ipcdetail::DoOpenOrCreate:
shmflg |= IPC_CREAT;
break;
default:
{
error_info err = other_error;
throw interprocess_exception(err);
}
}
int ret = ::shmget(key.get_key(), size, shmflg);
int shmid = ret;
if((type == ipcdetail::DoOpen) && (-1 != ret)){
//Now get the size
::shmid_ds xsi_ds;
ret = ::shmctl(ret, IPC_STAT, &xsi_ds);
size = xsi_ds.shm_segsz;
}
if(-1 == ret){
error_info err = system_error_code();
throw interprocess_exception(err);
}
m_shmid = shmid;
return true;
}
inline bool xsi_shared_memory::remove(int shmid)
{ return -1 != ::shmctl(shmid, IPC_RMID, 0); }
#endif //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
} //namespace interprocess {
} //namespace boost {
#include <boost/interprocess/detail/config_end.hpp>
#endif //BOOST_INTERPROCESS_XSI_SHARED_MEMORY_HPP
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